Clear Connect RF technology commercial overview
TM
Lutron® pioneered the RF light control market more than a decade ago. The careful design
considerations taken prior to launching our first product, and progressive design refinements
since, have transformed a pioneering company into the recognized industry leader.
This document presents highlights of the technologies and topologies behind our highly successful
RF products. For more in-depth coverage, please request the 16-page whitepaper (P/N 367-1234),
which is also available online: www.lutron.com/technical_info/
Lutron requirements:
When Lutron set out to design the first RF light
control System (LCS), several key specification
points were non-negotiable:
The system had to be “ultra-reliable” (working to
specification in every application—at the time of
installation and thereafter)
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Systems capable of 2-way RF communications
to provide system feedback (an industry first)
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Simple installation: no special tools, methods
or rewiring (requiring dimmers without neutral
wires)
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Complete RF product offering (to include
sensors, system interfaces, handheld devices
load controllers and more)
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Elegant aesthetics would not be compromised
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The investigation of
communication technologies:
Several engineering man-years were spent in
determining the best method for creating a “true
RF retrofit” LCS. The following are a few of the
items we considered in depth:
Different frequency bands (400 MHz, 900 MHz,
2.4 GHz…)
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Different regulatory requirements–from a global
perspective (FCC, NOM, IC, CE, R&TTE,…)
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Network and protocol designs (distributed vs.
centralized intelligence, fixed vs. mesh network,
group vs. directed commands)
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RF interference studies were conducted
to determine the best frequency bands for
operation and “real-world” RF activity levels
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Our findings:
Every RF system could be compromised by
interference—regardless of sophisticated
hopping or modulation techniques
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Higher RF power does not ensure reliable
communications—the risk of interference in high
power bands outweighs the benefits of higher
power
•
Frequency bands allowing “continuous”
transmissions—such as those with phones,
wireless routers and baby monitors—would be
problematic
•
Lower frequencies are attenuated and reflected
less through construction materials than higher
frequency signals (analogous to low-frequency
”bass” audio signals)
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Clear Connect RF technology commercial overview
TM
The Conclusion FCC Part 15.231
Our investigations determined that the rules
and other products operating under FCC Part
15.231 (similar operating regulations are used
internationally—identified by different regulation
numbers) were ideal for a robust LCS. Lutron®
evaluated all devices operating in this band, and
chose frequencies that did not line up with other
popular devices. In brief, the rules and benefits
of operation under 15.231 are as follows:
Devices may not transmit continuously, and may
not “poll” (making for an essentially silent band)
The higher operating frequency of these devices
is attenuated and reflected by building materials
more so than the lower frequency Clear Connect
devices.
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Clear Connect devices have insignificant
bandwidth competition and are designed to
be densely co-located in a building without
interference. The designs can operate for years
on a battery allowing products that require
no wiring and can be easily relocated during
building reconfigurations.
•
•
Generally, activity is initiated by a button press or
someone entering a room (“event driven” activity)
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Plenty of frequency bandwidth (~170 MHz) for
products to share
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Long, stable history with no proposed
rule changes
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Message Delivery –
A “fixed network”:
Once the best operating rules and frequencies
were selected, optimum network design was
required. Fixed and mesh networks were
analyzed. While both topologies have their
strengths, we determined that fixed networks
better served the unique needs of an LCS.
Devices are relatively “low power” (fractions
of a Watt)
•
Great for high-density applications: schools,
office buildings, industrial buildings, MDU
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Bands with similar definitions are available
globally
•
•
•
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Messages move quickly and consistently
through the network
Location of source and destination device do not
affect performance
Scales to larger systems without performance
degradation
Easier network troubleshooting
•
Why not 900MHz or 2.4GHz?
The FCC rules in these bands permit alwayson, high-power transmissions from devices
such as WiFi routers, Bluetooth devices and
cordless phones. They require high data rates,
encryption, and complicated radio techniques to
mitigate interference from the potentially many
competitive, co-located devices. These devices
have high power draws and cannot operate for
years on a battery.
•
Clear Connect RF technology commercial overview
TM
Message Content –
Group Commands:
LCS protocol must be efficient to achieve lights
that react imperceptibly fast and simultaneously
(not lights staging on one after the other – the
“popcorn effect”). Directed commands that are
used in other systems cannot achieve Lutron®
performance in lighting actions involving
numerous lights.
Some highlights of Group Commands:
Commands are very short – “Preset 01” –
propagated through the network very quickly
Lutron RF Experience
Pioneered RF LCS category
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Over 1 million devices sold
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More than a decade of production, sales and
installation
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Diverse product lines: RadioRA® 2,
HomeWorks® QS, Maestro Wireless®,
GRAFIK Eye® QS, Stanza, Sivoia® QS,
RadioTouchTM and Radio Powr SavrTM
•
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System devices have distributed intelligence
(memory) and have been preprogrammed with
all the information required to react
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Scales from a few to many devices with no
performance degradation
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Requires ownership, common hardware,
and coordination of all system devices (not
achievable when products are from different
manufacturers)
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RF Technology
Seven RF-specific patents
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Fixed network message delivery topology
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Fast group or preset commands (not directed
commands)
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Unique device addresses and serial numbers
(ensures that co-located systems will not
cross-talk)
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Easy and reliable integration (Ethernet, RS232,
IR, CCIs and CCOs)
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www.lutron.com
World Headquarters 1.610.282.3800
Technical Support Center 1.800.523.9466 (Available 24/7)
Customer Service/Quotes 1.888.LUTRON1 (1.888.588.7661)
© 04/2011 Lutron Electronics Co., Inc. I P/N 367-2130 REV A
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